1. Field of the Invention
The present invention relates to a measuring apparatus and a measuring method for measuring a dimension of a micropattern formed on a sample using an electron microscope.
2. Description of the Related Art
In a manufacturing process of a semiconductor device in which multiple layers of microscopic circuit patterns are formed, measurements are made to see if the pattern is processed as designed, or if there is any variation in the pattern dimension. For this pattern measurement, a scanning electron microscope (SEM) suitable for dimensional measurement of the micropattern is widely used. The SEM irradiates a measurement sample with an electron beam while scanning and detects a signal electron (secondary electron and backsattered electron) secondarily obtained from the measurement sample, thereby obtaining a scanned image (SEM image). Because a generated amount of the secondarily obtained signal electron depends on a pattern shape, a material, and the like, the measuring target pattern can be measured using a contrast of the SEM image. The measuring apparatus and the measuring method using the electron microscope are disclosed in, for example, Japanese Unexamined Patent Publication Nos. 2004-140280, H07-27549, and 2009-110969.